Multi-mode wireless communication terminals capable of communicating on GSM cellular networks and using unlicensed mobile access (UMA) technology, for example, WiFi or Bluetooth, are known generally. When a GSM/UMA mobile station is camped on an unlicensed mobile access point, the GSM radio operates in a null, hibernate or passive mode during which power consumption is substantially reduced. When the UMA link quality deteriorates during a UMA call, the mobile station must handover to a cell in the GSM network. In some instances, the UMA call may be dropped before selection on the GSM network is completed, for example, when the UMA link quality deteriorates rapidly.
In one known implementation, periodic selection is performed every 30 seconds on the GSM network when the mobile station is camped on a UMA network to ensure prompt rove out or handover to GSM. Frequent scanning of the GSM network however increases the burden on processing resources, since the UMA and GSM stacks are active simultaneously. The relatively high frequency rate at which GSM selection is performed thus draws substantial current, which adversely affects battery life.
The various aspects, features and advantages of the disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below.